Whether level 1 predictors should be centered per cluster has received considerable attention in the multilevel literature. While most agree that there is no one preferred approach, it has also been argued that cluster mean centering is desirable when the within-cluster slope and the between-cluster slope are expected to deviate, and the main interest is in the within-cluster slope. However, we...

introduction: rotary nickel-titanium (niti) instruments are thought to allow shaping of narrow, curved root canals more efficiently and more effectively than stainless steel hand instruments. however, the continued search for even more effective and safer instruments has resulted in new rotary systems being introduced on a regular basis. the aim of this study was to compare shaping parameters o...

self-centering pier (scp) has been viewed as a remarkable accomplishment which is able to sustain major lateral loading with reduced structure damage in seismic engineering. stiffness deterioration observed in experiment is vital for the seismic performance of self-centering concrete pier. in this contribution, the associated stiffness deterioration with respect to the structural damage is mode...

A new application of the mean centering of ratio spectra method is proposed for estimation of the rate constants of second order reactions, using kinetic-spectrophotometric data. The method is based on the mean centering of the ratio spectra to obtain a kinetic profile of the product. Using computational fitting, the rate constant can be obtained without any ambiguity. An interesting feature of...

AIM One Shape Apical 1 (OSA 1) is a new file for preparing the apical aspect of the root canal after One Shape (OS, Micro Mega, Besançon, France). This study compared apical transportation and centering ratios in curved root canals, which were instrumented with ProTaper Next (PTN, Dentsply Tulsa Dental Specialties, Tulsa, OK) up to size X3 and with OS up to OSA 1. MATERIALS AND METHODS Forty-...

AIM The aim of this study was to compare canal transportation and centering ability of Twisted files (TF) and ProTaper (PT) files with conventional stainless steel (SS) K files. MATERIALS AND METHODS Thirty mandibular premolar teeth with root curvature of 25 to 35° were selected. The samples were randomly divided into three groups of 10 each according to the type of files used for instrumenta...

background: the aim of this study was to evaluate apical transportation and centering ability of single-fi le instruments, waveone primary, with full rotation versus reciprocation movement using cone-beam computed tomography (cbct) analysis in curved mesiobuccal (mb) root canal of human mandibular molars. materials and methods: thirty mb canals of mandibular molars were randomly divided into tw...

The aim of this work is to develop and validate simple, sensitive, selective and cost effective spectrophotometric methods for the determination of tetramisole hydrochloride in the presence of its alkali-induced degradation product without preliminary separation. These methods namely ratio difference [11,12], derivative ratio [13,14], mean centering [15,16] and continuous wavelet transform [17,...

The aim of this work is to develop and validate simple, sensitive, selective and cost effective spectrophotometric methods for the determination of tetramisole hydrochloride in the presence of its alkali-induced degradation product without preliminary separation. These methods namely ratio difference [11,12], derivative ratio [13,14], mean centering [15,16] and continuous wavelet transform [17,...